The correct order of ionisation enthalpy of C, N, O, F is

Options

A. `F lt N lt C lt O`
B. `C lt N lt O lt F`
C. `C lt O lt N lt F `
D. `F lt O lt N lt C`

Answer

C

Explanation

In a period , the value of ionisation ethalpy increases from left to right with irregularity where the atoms have somewhat stable configurations . In nitrogen (second period) 2p- orbitals are half filled leading to higher value of ionisation energy than oxygen.
Hence the order is
`underset((1086))(C) lt underset((1314))(O) lt underset((1402)) (N) lt underset((1681))(F) " " kJ mol^(-1)`